Hot Tub Wiring


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Old 07-10-13, 11:25 AM
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Hot Tub Wiring

I had an old tube running from a Federal Pacific home panel with 40 amp breakers in it. The breakers were wired with 10/3 copper cable running approx. 50 ft. to the tub. I want to upgrade with a tub requiring 50 amps. Will the 10/3 cable handle the 50 amp. load?
 
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Old 07-10-13, 12:27 PM
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Will the 10/3 cable handle the 50 amp. load
It won't even handle the 40 amp load you have and cable was probably never code compliant if this is not inside your house. If the new hot tub is 240 volt not 120/240 volts you only need need two hots and an insulated ground. Cable can not be used if this is outside because it must have an insulated ground.

If there is not GFCI protection at the Hot Tub the breaker in the panel must be GFCI but given the cost of an FPE GFCI if you can even find one and the safety concerns for FPE panels might be time to change your main panel..
 

Last edited by ray2047; 07-11-13 at 08:01 AM. Reason: Singular pronoun required.
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Old 07-11-13, 05:57 AM
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Exclamation Yikes!

Just last week, I had a customer report they might feel electricity when they touch the hot tub water. Obvious answer: Stop touching the hot tub water!

The tub was wired without any ground at all. I could measure up to 98 Volts between the water in the tub and the dirt next to it. I even spent extra time looking for a ground rod or strap. How this tub ran for six years without killing anyone is a mystery to me.

My only guess: the wood decks protected them until they rotted out. When they removed the deck, they started 'feeling the tingle' because they were standing directly on the concrete pad with wet feet.

Swimming pools, spas, hot tubs and fountains have a separate section of the code (680) because they present particular hazards: water + electricity. The code in section 680 often overrules other code wherever there is a conflict.

In many jurisdictions, if you are replacing the entire tub, everything will have to meet current code requirements including a permit and inspection. (I've had some inspectors suggest they wanted a new inspection if I disconnected and reconnected the input power to change out a circuit board!)

However, an inspection on a newly installed hot tub is probably the cheapest form of insurance you can buy: a government official telling you the tub is safe.

The first question (already mentioned in the first reply) should be: Will the old FP panel support the extra amperage of the 220V hot tub? If not, and you wire it anyway, you risk starting a fire in your panel. Your 220V tub probably requires 4 #8 or larger wires. Some tubs use a Load Neutral. Some don't. All require GFCI protection.

Sorry, but if your questions start with basic things like what wire size to use (at least you didn't ask what color wire to use), you should probably hire a licensed electrician to install the new tub.

If there's one project you want to get right on the first try, it's probably the one where you connect 220V, 50 Amps to water and then sit in the water up to your neck. If you know you can do it yourself safely, at least get an inspection. If you have even the slightest doubts at all, hire a professional.

Here are the codes I see violated most often:

680.12 Maintenance Disconnecting Means. One or more means to simultaneously disconnect all ungrounded conductors shall be provided for all utilization equipment other than lighting. Each means shall be readily accessible and within sight from its equipment and shall be located at least 1.5 m (5 ft) horizontally from the inside walls of a pool, spa, or hot tub unless separated from the open water by a permanently installed barrier that provides a 1.5 m (5 ft) reach path or greater. This horizontal distance is to be measured from the water�s edge along the shortest path required to reach the disconnect.

680.44 Protection. Except as otherwise provided in this section, the outlet(s) that supplies a self-contained spa or hot tub, a packaged spa or hot tub equipment assembly, or a field-assembled spa or hot tub shall be protected by a ground-fault circuit interrupter.
A. Listed Units. If so marked, a listed self-contained unit or listed packaged equipment assembly that includes integral ground-fault circuit-interrupter protection for all electrical parts within the unit or assembly (pumps, air blowers, heaters, lights, controls, sanitizer generators, wiring, and so forth) shall be permitted without additional GFCI protection.
B. Other Units. A field-assembled spa or hot tub rated 3 phase or rated over 250 volts or with a heater load of more than 50 amperes shall not require the supply to be protected by a ground-fault circuit interrupter.
C. Combination Pool and Spa or Hot Tub. A combination pool/hot tub or spa assembly commonly bonded need not be protected by a ground-fault circuit interrupter.

312.2 Damp and Wet Locations. In damp or wet locations, surface-type enclosures within the scope of this article shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet or cutout box, and shall be mounted so there is at least 6 mm (�-in.) airspace between the enclosure and the wall or other supporting surface. Enclosures installed in wet locations shall be weatherproof. For enclosures in wet locations, raceways or cables entering above the level of uninsulated live parts shall use fittings listed for wet locations
 
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Old 07-11-13, 07:18 AM
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...Will the 10/3 cable handle the 50 amp. load?
No. Big time no.

Some 50A tubs have a setting (jumper) to restrict themselves to a 30A feed. Which 10/3 is good for. 40A breakers on 10/3 are illegal and unsafe.

Otherwise look in the tub's instruction manual. It may list mandatory wire sizes. Or it may say follow the NEC.
 
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Old 07-11-13, 08:10 AM
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Excellent post by new member HotTub tips with a couple of minor corrections. Voltage is not 220. It is 240 volts. You need four wires only if you need a 120/240 supply. You need #6 not #8 for a 50 amp breaker. Ground rods are not used but bonding of all metal is required and that may include a burried bonding ring. Note bonding and grounding are two separate things.
 
 

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